#include <algorithm>
#include <cmath>
#include <cstdio>
#define N 550
using namespace std;

int n, C;
int a[41];
double max_ans = -1;
bool f[N][N];

double heron(int a, int b, int c) {
	double p;
	p = (a + b + c) / 2;
	return sqrt(p * (p - a) * (p - b) * (p - c));
}

bool check(int a, int b, int c) {
	return a + b > c && a + c > b && b + c > a;
}

int main() {
	// freopen("testdata.in", "r", stdin);
	// freopen("testdata.out", "w", stdout);

	scanf("%d", &n);
	for (int i = 1; i <= n; ++i) {
		scanf("%d", &a[i]);
		C += a[i];
	}
	f[0][0] = 1;
	for (int i = 1; i <= n; ++i) {
		for (int j = C / 2; ~j; --j) {
			for (int k = j; ~k; --k) {
				if ((j >= a[i] && f[j - a[i]][k]) || (k >= a[i] && f[j][k - a[i]])) {
					f[j][k] = true;
				}
			}
		}
	}
	for (int i = 1; i <= C / 2; ++i) {
		for (int j = 1; j <= i; ++j) {
			if (f[i][j] && check(i, j, C - i - j)) {
				max_ans = max(max_ans, heron(i, j, C - i - j));
			}
		}
	}
	if (max_ans == -1) {
		printf("-1");
	} else {
		printf("%d", (int)(max_ans * 100));
	}
	// fclose(stdin);
	// fclose(stdout);
	return 0;
}